Soft robots and biomedical implants that reconfigure themselves upon demand are closer to reality with a new way to print shapeshifting materials.
Rice university researchers developed a method to print objects that can be manipulated to take on alternate forms when exposed to changes in temperature, electric current or stress.
The researchers think of this as reactive 4D printing. Their work appears in the American Chemical Society journal ACS Applied Materials and Interfaces.
They first reported their ability to make morphing structures in a mold in 2018. But using the same chemistry for 3D printing limited structures to shapes that sat in the same plane. That meant no bumps or other complex curvatures could be programmed as the alternate shape.
Overcoming that limitation to decouple the printing process from shaping is a significant step toward more useful materials.
These materials, once fabricated, will change shape autonomously.
A reactive 3D printing method is developed that decouples printing and shape-programming steps, enabling a broad range of complex architectures and virtually any arbitrary shape changes. This method involves first printing liquid crystal elastomer (LCE) precursor solution into a catalyst bath, producing complex architectures defined by printing. Shape changes are then programmed through mechanical deformation and UV irradiation. Upon heating and cooling, the LCE reversibly shape-shifts between printed and programmed shapes, respectively.
Future work will further optimize the printing formula and use scaffold-assisted printing techniques to create actuators that transition between two different complex shapes.
This opens the door to printing soft robotics that could swim like a jellyfish, jump like a cricket or transport liquids like the heart.
News Source: Rice University
